1. Field of the Invention
The present invention is concerned with new derivatives of corynantheine and especially tetrahydrocorynantheine (THCN), as well as the pharmacologically acceptable acid-addition salts of these compounds, processes for the preparation thereof and pharmaceutical compositions containing these compounds, i.e. the use of the new corynantheine derivatives as medicaments.
2. Description of the Prior Art
A number of medicinal specialities are available commercially for the treatment of circulatory disturbances and for the therapy of high blood pressure. Nevertheless, there is still a number of cases of treatment in which the available preparations are ineffective or which are unsatisfactory because of their specific side effects or of their chronological course of action.
Thus, for example, raubasine (ajmalicine or .delta.-yohimbine) has been used as an active substance for decades in the therapy of circulatory disturbances. However, it has only a relatively short period of activity and, therefore, a continuous repetition of the administration thereof over short intervals of time is necessary.
Consequently, there is still a need for pharmacologically-active compounds and medicaments which possess a long-lasting blood pressure-lowering effectiveness but, at the same time, are as free as possible of unpleasant side effects.